MOVIMIENTOS DE TIERRAS

The primary objective of this study was to examine the role of shell artefacts in the pre-Columbian

technological system by means of an explorative usewear study. Below, first the methodological aspects of usewear analysis in general and specifically of shell implements will be evaluated (Ch. 6.2). The results of the

analysis from the other tool categories make it possible to examine the role of their relationship and of shell implements in particular. The following paragraph (Ch. 6.3) focuses on the choice of raw materials for tools and ornaments. The reconstruction of these choices in the technological system was the second objective of this study. It will be demonstrated how functional analysis contributes to our knowledge of the technological choices made. Furthermore, it will be shown how a distinction can be made between cultural preferences and physical constraints. Data from different contexts, including archaeological, palaeobotanical, ethnographic and ethnohistorical information was gathered to form the basis for an experimental reference collection. The results also formed the basis for the reconstruction of domestic crafts and subsistence activities, the third objective of this study. In the fourth paragraph (Ch. 6.4) a description of the variety in household activities will be described. The diachronic changes that were observed are also presented there. To conclude some suggestions for further research will be presented (Ch. 6.5).

6.2 thepossIbIlItIesandlImItatIonsoffunctIonalanalysIs 6.2.1 lowandhighpower, FormandFunction

In earlier studies of shell artefacts, ascribed function was based on analogy, morphology and the presence of functional edges. In particualr the so-called recurrent forms or expedient tools have been debated (Armstrong 1979; Dacal Moure et al. 2004; Jones O’Day and Keegan 2001; Keegan 1981, 1984; versteeg and Rostain

1997). In some cases low magnifications were used (Cartwright et al. 1991; Lundberg 1985). In my opinion however, only high power analysis sheds light on the actual use of a tool, while the low power approach may only lead to a hypothesis on the possible function of an artefact or to low level inferences. Polish can only be interpreted with the high power technique. Although well-developed polishes might be visible with low power, the diagnostic features are only observable with high power. The choice for one of both methods depends on the quality of the material (suitability for high power analysis) and the questions asked. The method makes it possible to overcome the traditional form/function relationships. In the case of the pre-Columbian assemblages of Morel and Anse à la gourde virtually the entire tool-kit consists of artefacts without a formal typology. Part

of the shell implements, the majority of hard stone tools, all flint artefacts and the coral and used pottery sherds

have not been made in a standardized way. Functional analysis makes it possible to classify these tools on the basis of inferred function instead of morphology. Functional analysis makes it moreover possible to add an organic component to the archaeological evidence. The traces preserved on the tools give us information about these materials, which otherwise do not normally survive.

6.2.2 theso-calledrecurrentForms

In the specific case of shell tools, bivalve shell implements and other expedient tools are especially interesting

for functional analysis. It is generally accepted that the majority of the bivalve shells should be interpreted

as tools, but there are no indications about the tasks performed since they hardly show modifications. It has

been demonstrated that traces are visible on both the micro- and the macroscopic scale and that they can be

distinguished from secondary modifications and manufacturing traces. The macroscopic use modifications may still be interpretable even in the case of minor secondary modifications, although we have to be content with

less detailed inferences of tool use. Use-retouch and intentional retouch can be separated on the basis of their

distribution and regularity. Secondary modifications are distributed randomly over the shell surface and consist

of rounding and unevenly distributed edge removals.

The so-called recurrent forms that were found in Anse à la gourde were always weathered and worn as the result of taphonomic processes. The sample of these tools studied with the high power technique displayed no evidence of use. They should be considered as discard of food or shell artefact production. It is very likely that these recurrent shapes are the result of recurrent natural and/or anthropogenic breakage patterns that are related to the form and robustness of the various shell species. Trampling and abrasion, and especially rolling

in the coastal surf are more plausible explanations for these shapes, rather than intentional modifications.

Microscopic analysis should be applied to collections of these presumed ‘tools’, especially in sites where the

tools with intentional modification are lacking. A microscopic pilot-study of expedient tools from the Bahamas,

Turcs and Caicos, Haiti and Jamaica (Jones O’Day and Keegan 2001) was carried out by myself. It has revealed that high power analysis provides the best method to distinguish between ‘actual tools’ and ‘recurrent shapes’. Although the shapes may occur regularly, only a small percentage indeed show traces of use.

However, real expedient use (in the sense of the execution of one short task) does not leave diagnostic traces.

6.2.3 methodologicalobservations

There are many similarities between the usewear analysis of flint and shell artefacts. The experimental

reference collections of both artefact classes display strong parallels in the microscopic traces and the distribution and characteristics of the polish. Thus, for the interpretation of shell artefacts use can be made of

the experimental flint collection. The environmental setting of the sites studied however, asked for experiments focused on specifically tropical domestic activities and the processing of local materials. Another specific difference between shells and most flint artefacts is the fact that many shells are shaped by polishing, resulting

in an abundance of manufacturing traces. These traces have to be separated from the traces that develop as a result of use. Experiments were directed at tool production as well as tool use. Celts especially display a mixture of traces. So, experimental tools were studied microscopically before and after use. The results demonstrated that a distinction can be made between manufacture and use on a high power level.

Unfortunately, taphonomic processes have a much greater effect on the surface of shell tools than on flint tools, resulting in retouch and abrasion. These secondary modifications can now be recognised however, when the

combination of microscopic and macroscopic traces is studied. In the case of the sites studied it was apparent that the tools found in Morel suffered from the formation of beach rock in the site. Consequently, it was harder

to interpret these shell tools than the ones from Anse à la Gourde, resulting in a less refined level of inference.

It should be stressed that functional analysis extends beyond the registration of usewear traces in view of the

differential expression and preservation. Specific worked material categories, such as fish and meat are often

underrepresented, the duration of use might have been too short to leave diagnostic traces and traces may have been lost because of resharpening or the occurrence of severe edge damage. Entire organic tool categories (wood, calabash) may be missing in the toolkit and expedient tools may not have been recognised. To approach the problem of expediency a quantitative approach towards the development of traces on shell implements is

required, as was done for flint (Van den Dries and Van Gijn 1997). To give the functional data a social meaning

they should be regarded in their context. The archaeological information provides data on available material sources. Ethno-historical and ethnographic data present ideas on the actual tasks carried out. ‘Cutting siliceous plants’ can thus be interpreted as being part of the domestic task of ‘making basketry’. Experimental data can be regarded in the same manner, providing hypotheses on possible activities.